Improvements in or relating to a material intake in printing machines

ABSTRACT

A material intake for webs in printing machines, in particular for easily stretchable and warped webs of material, for instance meshed material, is provided with an edge regulating system. A regulating roller is positioned in the material intake. The regulating movements of the regulating roller are executed axially. An intake plate follows the regulating roller and inclines downwardly at an increased angle with respect to a horizontal plane.

United States Patent [191 Eder et al.

[ Apr. 30, 1974 IMPROVEMENTS IN OR RELATING TO A MATERIAL INTAKE IN PRINTING MACHINES [75] Inventors: Johann Eder; Karl Mayer, both of Klagenfurt, Austria [73] Assignee: Johannes Zimmer, Klagenfurt,

Austria [22] Filed: Jan. 30, 1973 [21] Appl. N0.: 328,080

[30] Foreign Application Priority Data Feb. 8, 1972 Austria 995/72 [52] US. Cl. 226/20, 226/193 [51] Int. Cl B65h 25/26 [58] Field of Search 226/l8-23, 226/193; 198/202 [56] References Cited UNITED STATES PATENTS' 3,373,912 3/1968 Toensing. 226/20 11/1971 shew/00 ..226/21X l/l967 Jacobsen.....

Primary Examiner -M. Hens on Wood, .lr. Assistant Examiner-Gene A. Church Attorney, Agent, or Firm-Wenderoth, Lind & Ponack 7] ABSTRACT- A material intake for webs in printing machines, in particular for easily stretchable and warped webs of material, for instance rneshed material, is provided with an edge regulating system. A regulating roller is positioned in the material intake. The regulating movements of the regulating roller are executed axially. An intake plate follows the regulating roller and inclines downwardly at an increased angle with respect to a horizontal plane.

9 Claims, 2 DrawingFigures IMPROVEMENTS IN OR RELATING TO A MATERIAL INTAKE IN PRINTING MACHINES BACKGROUND OF THE INVENTION The present invention relates to a material intake for webs of material in printing machines, particularly for easily stretchable and warped material, such as meshed material, which material intake is provided with an edge regulating system.

Easily stretchable and warped webs of material, such as meshed material, because of their elasticity require a substantially tension free treatment in the printing machine, especially within the zone of material input until the zone where the web is placed or glued onto the printers blanket. Within this zone an edge regulating system is to be provided so as to achieve exact lateral positioning of the web, to compensate for incorrect winding and shifting of the web and to maintain the edges in constant alignment. In material intakes of the known type use is made of edge regulating systems ess'entially consisting ofa regulating roller onto which the web of material is shifted and whereby the regulating effect is achieved by tilting the regulating roller.

Such devices require, however, a considerable stretching of the web. In addition to the resulting stretching of the meshes, the tilting of the regulating roller together with the regulating movements thereof lead to the web of material being fixed onto the printers blanket in a distorted or wrinkled position, especially if the distance between the regulating roller and the fixing of theweb of material onto the printers blanket is short.

OBJECTS AND BRIEF DESCRIPTION OF THE INVENTION It is therefore the object of the present invention to provide a material intake in printing machines operable to correctly guide easily stretchable and warped webs of material into printing machines.

In accordance with the invention this object is achieved by the provision of a regulating roller in the material intake, the regulating movements of which are executed in a direction extending axially of the regulating roller, and being followed by an intake plate inclined downwardly with respectto a horizontal plane and serving as a region of steady flow for the Web in the direction of its travel.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be described with reference to the accompanying drawings without being limited to these examples wherein:

FIG. 1 is a material intake according to the invention which preferably is used in printing machines with flat screens and a discontinous intake of the web.

FIG. 2 shows variations from this embodiment for us in a rotary screen printing machine.

DETAILED DESCRIPTION OF THE INVENTION interrupts the light cell 8. If a.further light cell 10 is interrupted by the web, the impulse thereof operates to shut off the printing machine (emergency stop). After having passed the guide rollers 11,12 and the lifting rod 13 pivoted at the ends of the piston rods 14 of lifting cylinders 15 positioned at both sides of the frame of the machine, the web 1 arrives at the regulating roller 16 which is driven, by means of flat belts fixed to a guide roller of the printersblanketll, at the circumferential speed of the guide roller.'The regulating roller 16 on its periphery is provided with a special covering, made for instance of knubbed rubber, in order to ensure that the web is taken along without slipping during the regulating movements of the regulating roller 16. According to the invention the regulating movements consist in that the regulating roller 16 is axially shifted to the left or to the right side of its neutral position at an adjustable speed, as soon as the web deviates from a predetermined adjusted edge position. The regulating movement in one or the other direction is initiated by detectors such as phototubes or pneumatic blast nozzles 17 surveying one or both edge's'of the web 1. The regulating movement advantageously is operated by a doubleacting pneumatic cylinder coupled with an adjustable, hydraulic throttle device to permit the regulation of the speed of movement.

For structural reasons the regulating zone is limited therefore, in case of heavily warped webs, owing to an inevitable minor slippage between the regulating roller and the web 1, and owing to the fact that the regulating roller 16 arrives at an end position, the regulating movement in response to the impulse of the detectors will stop. As soon as the regulating roller 16 arrives at oneof the two final end, positions the lifting device will operate. In operating the two lifting cylinders 15 the lifting rod 13 is lifted to such an extent as to disengage the web 1 and the regulating roller 16 whereupon the latter returns to its neutral position. In printing machines with discontinuous intake of the web, the lifting advantageously takes place during the dead phase. During this phase the hydraulic throttle movement is stopped in order to ensure a rapid return movement. When the regulating roller 16' has returned to its neutral position the lifting rod 13' will'be lowered by ventilating the lifting cylinders 15. After having passed the regulating system of web 1 arrives at an intake plate 18 which guides the web merely until it is acted on by the pressure roller 19 of the gluing device. According to the invention this intake plate has the function of providing a region of steady flow for the web. By reason of its length and especially by reason of its shape, a plate inclined downwardly in the direction of. travel of the web, it is proper to compensate for stretching and warping, whichto a certain extentmay also be the result of the movement of the regulating roller 16 over a portion of the web 1' corresponding to its length. A special advantage consists in providing an intake plate 18 in the form of a circular cylinder section with an inclination tending to increase in the direction of travel of the web, whereby the progressively decreasing frictional force between web 1 and intake plate 18 effect a favorable tension balancing.

In FIG. 2 there is shown the lifting device for printing machines with continuous material intake. It differs from the embodiment shown in FIG. 1 in that instead of the lifting rod 13, a'lifting cylinder 20 is provided which rotates at the same circumferential speed as the guide roller 16 and which for the purpose of disengaging the web 1 and the guide roller 16, may be swung about the axis of the guide roller 16 when the latter has reached a final or end position. The angle of traverse of the lifting roller 20 is selected such that the guide roller 16 and the web 1 disengage during the return movement of the guide roller to its neutral position.

When the guide roller 16 has been restored its neutral position, the lifting roller 20 will return to its starting position where it does not contact the web 1.

We claim:

1. A material intake for webs in printing machines, in particular for easily stretchable and warped webs of material, for instance meshed material, said material intake including an edge regulating system operable to regulate the lateral position of said web and comprising a single horizontally mounted regulating roller positioned to be nondrivingly contacted over a portion of the upper circumference thereof by said web prior to passage of said web into said printing machine, said regulating roller being mounted for horizontal axial movement transverse to the width direction of said web; and an intake plate-means positioned to receive said web from said regulating roller and to allow said web to slide downwardly over the surface thereof, said intake plate means being inclined downwardly at a varying angle with respect to a horizontal plane.

2. Material intake as claimed in claim 1, further comprising means for regulating the axial movement of said regulating roller, said means being operated hydropneumatically at an adjustable speed.

3. Material intake as claimed in claim 1, whereby said regulating roller is operated at a circumferential speed corresponding to the intake speed of said printing machine.

4. Material intake as claimed in claim 1, further comprising non-contact'detector means for detecting the lateral position of said web for thereby regulating the axial movements of said regulating roller.

5. Material intake as claimed in claim 1, further comprising a lifting means positioned for removing said web from contact with said regulating roller when said regulating roller reaches an axial end position, said roller thereby being returnable to its neutral position.

6. Material intake as claimed in claim 5, wherein said lifting means comprises a lifting rod having an axis parallel with the axis of said regulating roller and mounted to contact said web, and pneumatic cylinder means mounted to selectively move said rod to move said we out of contact with said regulating roller.

7. Material intake as claimed in claim 5, wherein said lifting means comprises a lifting roller mounted in parallel with and to pivot around the axis of said regulating roller, said lifting roller revolving at the traveling speed of said web. I

8. Material intake as claimed in claim 1, wherein said intake plate means has the shape of a rotary cylinder section with an inclination increasing downwardly in the direction of travel of said web.

9. Material intake as claimed in claim 1, wherein said regulating roller has thereon an irregular coating of friction-enhancing material to prevent slippage of said web during regulating movement of said regulating roller in the axial direction thereof. 

1. A material intake for webs in printing machines, in particular for easily stretchable and warped webs of material, for instance meshed material, said material intake including an edge regulating system operable to regulate the lateral position of said web and comprising a single horizontally mounted regulating roller positioned to be nondrivingly contacted over a portion of the upper circumference thereof by said web prior to passage of said web into said printing machine, said regulating roller being mounted for horizontal axial movement transverse to the width direction of said web; and an intake plate means positioned to receive said web from said regulating roller and to allow said web to slide downwardly over the surface thereof, said intake plate means being inclined downwardly at a varying angle with respect to a horizontal plane.
 2. Material intake as claimed in claim 1, further comprising means for regulating the axial movement of said regulating roller, said means being operated hydro-pneumatically at an adjustable speed.
 3. Material intake as claimed in claim 1, whereby said regulating roller is operated at a circumferential speed corresponding to the intake speed of said printing machine.
 4. Material intake as claimed in claim 1, further comprising non-contact detector means for detecting the lateral position of said web for thereby regulating the axial movements of said regulating roller.
 5. Material intake as claimed in claim 1, further comprising a lifting means positioned for removing said web from contact with said regulating roller when said regulating roller reaches an axial end position, said roller thereby being returnable to its neutral position.
 6. Material intake as claimed in claim 5, wherein said lifting means comprises a lifting rod having an axis parallel with the axis of said regulating roller and mounted to contact said web, and pneumatic cylinder means mounted to selectively move said rod to move said web out of contact with said regulating roller.
 7. Material intake as claimed in claim 5, wherein said lifting means comprises a lifting roller mounted in parallel with and to pivot around the axis of said regulating roller, said lifting roller revolving at the traveling speed of said web.
 8. Material intake as claimed in claim 1, wherein said intake plate means has the shape of a rotary cylinder section with an inclination increasing downwardly in the direction of travel of said web.
 9. Material intake as claimed in claim 1, wherein said regulating roller has thereon an irregular coating of friction-enhancing material to prevent slippage of said web during regulating movement of said regulating roller in the axial direction thereof. 